BACKGROUND: Lidocaine's sedative effect has not been known well. The purpose of this study was to evaluate its sedative and cardiovascular effects during induction of anesthesia. METHODS: Twenty patients were randomly allocated to group I or II, with or without lidocaine 1.5 mg/kg intravenously (IV) before induction, respectively. The BIS, blood pressure and heart rate were measured at before and 2 minutes after lidocaine IV injection, preintubation, and 1, 2, 3 and 5 minutes after tracheal intubation. The enflurane concentrations were continuously maintained at 2 volume%. RESULTS: The BIS of group I was more decreased at 1 and 2 minutes after intubation than those of group II. The systolic blood pressures of group I were less increased at 1 and 2 minutes after intubation than those of group II. The diastolic blood pressures and heart rates of group I were not different from those of group II at each stage of the procedure. CONCLUSIONS: Lidocaine reduced BIS and blunted the intubation-induced systolic hypertensive response. In addition it is thought that it has a sedative effect and is effective to maintain cardiovascular stability after tracheal intubation.